The article investigates the effect of the specific magnetic susceptibility $\chi_{0}$ of 06ХН28МДТ alloy (similar to AISI 904L steel) on its corrosion behaviour in recycled water of enterprises, which most often has a pH of 4–8 and a chloride concentration of up to 600 mg/l. Under such conditions, heat exchangers made of this alloy melt can be subject to pitting. Their resistance to pitting corrosion is estimated by means of the critical temperatures (CPT) in model-recycled water with the following parameters. In particular, it has been found that the chlorides’ concentration within them has a more intense effect on the alloy CPT than their pH, since it increases up to 8°C with an increase in pH from 4 up to 8 and up to 11°C with a decrease in chlorides’ concentration from 600 down to 350 mg/l. It is found that, in the model recycled water with pH 4 and chlorides’ concentration of 350 mg/l, the CPT of the alloy decreases from 53°C down to 46°C, and with chlorides’ concentration of 600 mg/l from 42°C down to 38°C with an increase in its parameter $\chi_{0}$ from 2.86 m$^{3}$/kg up to 3.09 m$^{3}$/kg. However, its further increase up to 3.38 m$^{3}$/kg contributes to the elevation of the CPT up to 49°C in media with pH 4 and 350 mg/l and up to 40°C with pH 4 and 600 mg/l. This corrosion behaviour of the alloy is due to the synergistic effect of the alloy high $\chi_{0}$, the maximum content of titanium nitrides and sulphides, and the characteristic features of the selective dissolution of $\Delta$Cr, $\Delta$Ni and $\Delta$Fe from pits. In particular, under such conditions, they are stable and develop steadfastly, since the coefficients of selective dissolution of Cr $Z_{Cr}$ < 1 and Ni $Z_{Ni}$ > 1